Feed gear antioverload device



Oct. 16, 1934. D. c. KLAUSMEYER 1,976,944

' FEED GEAR ANTIOVERL OAD DEVICE I Filed Jan. 20, 1931 4 Sheets-Sheet l awuawcoz 95% 5x50 and W Y M1 Oct. 16, 1.934. D. c. KLAUSMEYER- 1,976,944

FEED GEAR ANTIOVERLOAD DEVICE Filed Jan. 20, 1931 4 Sheets-Sheet 3 PA W0 6 KLAUSMEYEIF Oct. 16, 1934- D. c. KLAUSMEYER I FEED GEAR AN TIOVERLOAD DEVICE 4 Sheets-Sheet 4 Filed, Jan. 20 1951 awvwtoz 5M EEM Y3 E M N 4R0 0 J AP 1- Y K R m c a m H M Y P B wot/"$134 Exswron M 1 M Patented Got. 16, 1934 FE D ems ANTIOVERLOAD DEVICE David C. lflausmeyer, deceased, late of Cincinnati, Ohio, by H. Henry Sundermann, executor, Cincinnati, Ohio, .assignor to The ,Cincinnati Bickford Tool Company, Cincinnati, Ohio, a

a corporation of Ohio 1 Application January 20, 1931, Serial No. 510,052

3 Claims. (01. 77-32) This invention has'to do with safety devices for machine tools and is particularly concerned with devices designed to prevent fracturing of the machine elements in the event that the given machine. l w i I I Y fIt hasrfor its main object to provide a device for suspending theoperatlon of one or more of the power transmission mechanisms of a ma- .5 tooling forces tend to exceed the capacity of a chine tool whenever the force requiredto overcome the work resistance exceeds a predeterminedmaximum.

further object of this invention is to provide a. safety device for a machine tool that-will efiectively transmit motion from one shaft to another "and which will automatically suspend thevdrive whenever thepowerrequirements are exceeded, and" resume the drive when the value of the load upon the driven element is again .1 2.0 reduced to a normal value; 7

Still another object isto provide a-safety device for. the :feed works of a drilling machine which will automatically suspend the feed ofa drill:- spindle whenever-there is an overloading of the. parts, and to so construct the device that it will: be impossible under normal conditions of operation to vary the effectiveness thereof but nevertheless be capable "of'readjustment upon dismantling of the unit. In this way the unit .30 may be adjusted to'carrygreater or lesser loads asidesired and theunit again sealed in an 'effec tive manner to prevent tampering therewith by an unskilled or unauthorized operaton- As an additional refinement it is proposed to construct a device of Strong rugged character and one that will operate and transmit the required power over long periods of usage without interruption or attentionthereto. a

Such a device; it will be observed is in" many respects superior to theshear-pin-safety devices,- and is peculiarly adapted formachine tools in which there are one or more transmissions for driving the tool or work-piece and one or more transmissions forfeeding the tool relative'to the Work. In these types of machines, were both drives positive under all conditions, as is customarily'the-case, damaged tools or workpieces are of frequent occurrence, and this is due, primarily; to the overloading of the parts; as by an unforeseen increase in the work resistance, or by. the carelessness of the operator in applying a driving'force beyond the capacity of the ma-- chine, tool,- or work-piece.

' This invention proposes to overcome the inherent disadvantages of the prior transmissions and to eliminate all possibility of the fracturingof the machine elements or work-pieces, by con-- structing a safety mechanism for the transmis- 1 sion, which will automatically suspend the drive when the load exceeds a predetermined value, 6 0

and which will automatically take hold or resume the drive when the load is removed or decreased as'the case may be. r 1 A In carrying out the objects of this invention it is proposed to arrange in the driving transmission a multi-disc power transmitting device having one set of discs engaged by the driving element and one set of discs, intervening those of the first set, engaged by the driven-element and. With-resilient means of a strength sufficient to maintain driving relation betweenthe discs under normal loads. The parts' are so arranged that the two sets of discs will move rela tive to eachother and suspendthe drive inthe event that the tooling forces create-stresses in the mechanism in excess'of their normal ca-' pacity. In this Way there is provided *a safety device'fora driving mechanism which is entirely automatic in its operation and one; that will function indefinitely without attention. 7 1 Unwarranted tampering of the mechanism by an unskilled operator hasbeen anticipated in this arrangement-by enclosing the device in a. suitable housing which is adapted to be initially sealed before the unit is placed in operation. The machine is thereby protected against an operators tendency to vary the tension inthe unit and thusvary its driving power-and defeat the purpose for which it isinstalled in the machine. f r I Other objects and advantages will be in part indicated in the following description and in part rendered apparent therefrom in connection with the annexed drawings. I

To'enable others skilled in the art so fully to apprehend the underlying features hereof that they may embody the same in the various ways contemplated by this invention, drawings depicting a preferred typical construction have been annexed as a part of this disclosure and, in such drawings;like charactersof reference denote corresponding parts throughout all the views, of which:--

Figure 1 is an assembly view of a--representative type of machine tool incorporating this invention. Figs. 2 and 3 are front and side sectional views respectively, of the head of the machine tool depicted by Fig. 1, and illustrating portions of the spindle speed .and feed trains. Fig. 4 is. a diagrammatic View. of the spindle driving train and incorporating the anti-overload device in the spindle feed train. Fig. 5 is an enlarged sectional view of the overload device and its relation with a driving and a driven element Fig. 6 is aplan view thereof,

partly broken away better to illustrate the rela-' tive positions of the discs and their locking means. 7 I

A preferred embodiment of this inventionis to the spindle drive and feed gearing of a machine tool, such as for example,' of the radial t eu eees arx-u The h ad h s, a s n le-'1 r tat b a d trrvo a b mounte here n-an which cei es mo i e no er -in reverse directions f om a prime. mover 8,, mou ted up .v h rm,

through an arm shaft 9;, and a variable speed transmiss on s emroa ie b the head.

. E ise-12:and i s ra e p ns of he seams contained thefldrill head -5' and Fig. 4 illusrates dias amma call he en re train. from thea m she ta oth s in l 5 e from the. p ime moyerfi exi erethe he d a t ar her n thr u h; h bevele ars :9 a d t a to he vthanee sp ed meeha smam a e enra ly; ash. A sear un .10 i s da ounted upon thesha t c is adapt u o th moveme i f'the e tre ove 3.1 o. be po t ned so that-sea s 10 thane as may be e ective y me hed with the sea o l c and-a spectively ofsthee ar n t a. T e hre somes; o haft b; mo tin ied -.,-the,.eh ns :sear me hanism. .13! wh ch-comprise ears 2 a d b udit? th n t a d is respe vely.

speedsf sha t 'c, are s inldiv dedr b h two sea soar. un s .ia d. o the s eedohans s t e e nit .141, bei g a ap e to. be sh t 9y, ov rs-.2; o as to e asesears l M16102 or the.-; o i-end oisth reb .zp ridi twel spe ds; oifthee af dw As end b c sear speed change set D, actuated by the back gear lever .32, jprovidestwo additional changes in the sp eds, mak g at e of twe ty-f ur S ed to t e indl shaft 1. .-.1hos..o uto ceea nit 17 kc ed to shaft 7 is adapted. tobe moved downwardly so gas-to connect the drivethrough gears ;d -ancl d with the spindle shaft, as by rnansof clutch teeth 17 engaging clutch teeth l o e in he loo el mo nt d s a u 16, or moved upwardly so as to engage gears c Th e foregoing -briefiy describes the spindle lql fi ill itlflmfl fi l h transmission mecha" nism for feeding the spindlenaxiallyflat various rates istaken preferably from the'spindle and nowbe: explained. 1

The spindle shaft- ,7 also carries splined thereto :a feedgear 18 which isnconstantly in mesh with vagear 1 19 forming .a. part of the antioverload ideviceumounteduupon the feed shaft. i Liatrthe polweriinput endaofathe feed train. The

driving element 19 transmits the power to the shaft 1 and thence through feed change gear mechanisms E, F and G to a feed worm shaft h. The first change gear set E provides three feed changes, to wit, by meshing gears e e ,or 2 of gear unit 20 with the gears e e, or e respectively provided by the units 21 and 22 --mou-nted upon a second shaft g. The second iced change mechanism also provides three speed changes as follows: The gear unit 23 is adapted to be moved axially upon the splined hub of a clutch gear .9 so as to engage selectively gears f and F, c and T or f and i making thus far a total of nine speeds to the.

hub portion of gear 9 V The nine speeds are again divided by the feed change gear mechanism G which comprises the clutch gear unit 24 and the loosely mounted gear unit 25. When the .clutch element is moved up the gear g engages the internal clutch teeth formed in the gear unitr24 and any one of the nine speeds of the gear'g is transmitted through the clutch element 24,130 the feed shift h, but if the clutch element is moved down the drive is then through gearsjUg 92,1 93, and or to the feed shaft. Thus, eighteen feed rates are transmitted to the shaft h, and thence through worm .26, worm wheel 27, pinion shaft 28, gear and rack connection 29and 3O tothe translatable spindle sleeve 7 A control lever 33 having nine .positions controls the positioning of the finer feed change gear sets E and F, andcontrol lever 3.4 controls the shifting of the back gear or coarse feed change gear set G. As illustrated by Figs. 1, 2 and 3- all of the control leversare located within convenient reach-of the operator.

The foregoing description illustrates in a general way a multi-speed and feedtransmission mechanisms of adrilling machine, ,the various elements of which, under ordinary conditions of operation are capable of withstanding heavy loads. ,-I Iowever, if asafety meansis not provided for rendering-one of the gear trains inoperative-or ineffective in the event that there is ,an overloading of the parts or that the force employed tends, to exceed the maximum for which the, machine was designed, the excessive stresses; eifect'a' straining of the partsv and possibly a fracturing of the gears. Therefore, to insure: against damage to the machine and to prevent undue working stresses therein, this invention proposes to qprovide a safety device adaptedto, be inserted as a unit in the feed train for interrupting the drive whereverflthe workloadexfieeds a predetermined maximum. Ordinarily the I larger'tools are rotated at relatively slowgrates of speed but are usually given a coarsefeed. The feed train in this disclosure isso arranged that the feeding urge at spindle nose during' coarse feeds is less than that; delivered during the finer feeds, theresult is that a unit increase in work resistance produces greater stresses upon the initial gears of the feed works thanjwill a unitincrease in the work resistance when using finer feeds.

Under normal conditions of operation the maximum feed that can be applied to the smallersizes of drills is'not sufficient to harm the feed works because. the smaller dimensioned tools are the weaker of the two. Trouble is experienced, however, when using large tools underiheavy loads," for under these conditions the feeding power required to overcome the workfiresistance mayexceed the capacity of the elementspf :the :feedtrain and the parts thereof are liable it o break before the fbrealiing point of the'tool isreached. a

11 It. is proposed, therefore, to place a safety coupling in that-portion of the feed t'rainwhich issubjec'ted to the heaviest loads, and to adjustthe' device 's'otthat it will suspend the drive when the feeding forces employedexceed apredetermined value;

For efiicient-operation a safety coupling of speed itsefiiciency remains constant irrespective of the possible changes which may be later effected in the ultimate output speedcor force.

The safety device S is. constructed and adjusted to carry the heaviest normal load, within the capacity of a' given machine, and comprises, essentially, a base plate member 35 having gear teeth 19 cut on the periphery thereof, and which is loosely mounted upon the feed shaft f. A driven element 36 is splined to the shaft 1 and held against axial movement thereupon by means of a lock nut 37; Movement of the driving member 35 is transmitted to the driven member 36 through a plurality of overlapping discs :i and k, the discs 7' having projections jwhich engage ,abutments 35 carried by the driving member; and the discs it having abutments k which engage abutments 36 of the driven member. Resilient means, such as springs 38 normally tend to maintain the discs in driving relation and exert a force substantially equal over the entire surface of the discs.

A cover plate 39 which provides recesses 40. for the seating and holding of the springs 38 in spaced relation, provides a means for sealing the unit against dirt, dust, etc., and also provides a means for effectively preventing unwarranted or easy adjustments thereof. Screws 41, accessible only from the underside of the base plate 35, hold the cover plate securely in place. Thus, the unit cannot be adjusted without first removing it from the machine and which, ob-

viously, will not be attempted by the average operator without him first consulting his superiors.

Once the unit S is removed from its normal position in the train, the frictional resistance between the discs is easily varied. For example, the placing of shims between the engaging faces of the cover and base plates 39 and 35, will tend to decrease the value of the torsional stress permissible before the drive therethrough is interrupted. The converse is true if the shims are placed between the discs 7' and the base plate 35, for under this condition the friction between the plates 1' and k will be increased and hence the value df the permissible load increased. Similarly, variations in the permissible loadto be carried may be made by varying the number or size of friction discs employed and/or by the substitution of springs of different values.

It will be noted that the drive to the safety unit and feed works is taken directly from the spindle and with such an arrangement, the

. determined maximum. I

heaviest loads onthe mechanism "occur during the slower rotating speeds of the spindle. As the power capable of being transmitted by the clutch is lesswhen driven at low speeds than when driven at high speeds, the drive through;

the feed'train is readily interrupted when the load at the spindle'nose increases beyond a pre- Without further analysis, the foregoing win so fully reveal the gist of this invention that 1'.

others can, by applying current knowledge,

readily adapt it for various utilizations by retaining one or more-of the features that, from the standpoint of the'prior art, fairlyconstitute essential characteristicsof either the generic or 9;,

specific aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, it is-1i;

claimed as new and desired to secure the following combinations and elements, or equivalents thereof, by Letters Patent of United States:

1. A radial drill having a translatable tool head and a rotatable and translatable spindle journaled therein, a multi-speed power transmission forrotating said spindle, combining a feed transmission comprising a plurality of change gear mechanismsin series for imparting translatory movements to said spindle at various preselected rates, said feed transmission being arranged to be driven by and directly from said spindle; and a safety device located in the input end of said feed transmission normally effective to maintain said feed transmission operative and adapted to interrupt the drive therethrough whenever the resistance to translator-y movement of the spindle exceeds a predetermined value, said safety device including a plurality of superimposed friction discs operatively connected with the initial power transmission elements of said feed transmission; and a single means for initially adjusting the power transw mitting value of said safety device and for sealing said device to prevent adjustment thereof during normal conditions of usage.

2. A drilling machine combining a tool head; a spindle rotatably and translatably journaled in said tool head; a prime mover; a multispeed driving transmission for rotating said spindle from said prime mover, said transmission including a plurality of sets of serially arranged speed change gears located in said head; a multispeed spindle feed transmission receiving motion from said spindle and subject to the variations of speed thereof, said spindle feeding transmission including a plurality of sets of serially arranged feed change gears; means for selectivefeed train is protected against overload while using high speed feed ratios.

3. A drilling machine combining a tool head; a spindle rotatably and translatably journaled a r r ssmafl in said t ol head; alprime mdve z a mlflti spsed driving transmission for rotating said spindle from said, prime mover, saidltransmission Jineluding. a plurality of sets of serially antanged speed change gears lqcatedin said head; a spindle feed driving gear on said spindle; a. mum-Speed I spindle feed a transmission receiving motion from the drive-gear: on said spindle-and subj set to the variatiqns of speed thereof, 7 said v spindle ieeding transmissionincludinga plumai ity of feedj-driye shafts located in said-head ands, plurality-pf sets pf serially arranged feed change gears mounted-0n said shafts; :meansfor selectiyely meshing said 'feed. change gearsyto "algzproduca any one \ofga plurality .of feed, rates in. .combinatiqn witheach rate of spindle rota- .gg 1 t ption; ndrmea s-smhodi in th d Of said' spindle feed transmission tor limiting to a. p ed ermined va th to que ad t d t be transmit-ted to, said spindle ieeding transmission b a d p ndle a dm ns n ludin a l p 1 pl n iocated bst een s id v d ,dxiv ea and the ini ia q i sa fee chan e ge r s t said coupling being adapted to transmit to the eed t 'ans fis on a redete m ned to e, and t n o s p w ereb th feed is Pmt e a a st pvei' p W i s ng hi s e eed rates. 1" SUN ERMANEa Executor 03 the Lqst Will m d Testament 0f Davi K va m yer, D c a d. 

